Near-Earth Objects
An NEO's orbit takes it within 1.3 AU of the Sun. The largest known NEO is over 40 km in diameter, but astronomers have found thousands of NEOs with diameters larger than 1 km. Anything smaller is too hard to see.
Magnetism
Since ancient times, people have known about some rocks that could attract iron. When these rocks were rubbed on other types of metal, they had the power to make them attractive too. These items could also push each other away, repelling each other.
- Magnetic Poles
Ancient Chinese thinkers figured out that a magnetic needle in water would always move to the same position. It would line up from north to south. This discovery led to the invention of the compass, which has been used ever since to help people find their way. The reason this works is that the Earth itself is a giant magnet.
Life on Earth
Planet Earth was formed around 4.5 billion years ago. The first signs of life began about 3.6 billion years ago, in the ocean. The water in the ocean protected organisms living there from the dangerous rays of the sun.
Life on Earth has taken billions of years to evolve. Life is characterised as anything which has the following traits:
Distances in the Solar System Poster
How far apart are the planets in the Solar System. The answer may surprise you!
The distance between the planets in our Solar System is not regular. The inner 4 rocky planets are spaced much more tightly than the outer 4 giant planets.
Download, print and display this free poster!
Make Your Own Star Wheel
Have you ever noticed how the night sky looks different every single day? This is because we are constantly moving in space so our view changes.